The Trailing Suction Hopper Dredger FRPD 309 working the south Channel of the Fraser River. FRPD stands for Fraser River Pile & Dredge. the ship in 112m in length, Can dredge to a Depth of 33m, and has a hopper capacity of 4630 m³. The Fraser River, as a river is prone to silting and requires constant dredging.